MacLochlainns Weblog

It’s possible folks didn’t notice but Mac OS X no longer includes XQuartz by default from Maverick forward. You need to download XQuartz and install it. I’d recommend after you install Xcode.

Launch XQuartz and then either use the bash shell it opens or open a Terminal bash shell session. Inside the shell, you might start Secure Shell (ssh) like this:

Mac-Pro-3:~ michaelmclaughlin$ ssh student@192.168.2.170
student@192.168.2.170's password: 
Last login: Thu Jun  4 14:33:37 2015
[student@localhost ~]$ xclock &
[1] 10422
[student@localhost ~]$ Error: Can't open display:

Granted that’s a trivial error and running the xclock X11 applications isn’t crucial, an error that makes it more important is the following from Oracle’s old Designer/2000 application:

FRM-91111: Internal Error: window system startup failure.
FRM-10039: Unable to start up the Form Builder.

This is the desired behavior. Secure shell (ssh) can’t run it unless you make the connection with the -Y flag. You should use the following syntax:

Mac-Pro-3:~ michaelmclaughlin$ ssh -Y student@192.168.2.170
student@192.168.2.170's password: 
Last login: Tue Jun  9 14:56:55 2015 from 192.168.2.1
/usr/bin/xauth:  file /home/student/.Xauthority does not exist
[student@localhost ~]$ xclock &
[1] 10760

You can safely ignore the .Xauthority does not exist warning message because it’ll create a .Xauthority file and store the magic cookie after the warning message. You should see the xclock program running in the upper left hand corner of your console, like:

It’s terrific that you don’t get a font warning like you typically would using UTF-8 on Linux. Nice that the Mac OS fonts are so well done that there isn’t a raised exception.

Using xclock or xeyes isn’t very useful as a rule, but this method also lets you run any of the Linux GUI applications. For example, the following gedit command lets you run the gedit utility from a Mac OS console. If you’ve installed the gedit plug-ins, you also can use the Terminal console on the remote system.

The process sequence for the command-line is shown below:

1030     1  /usr/sbin/sshd -D     - The root process launches the ssh daemon
3145  1030  sshd: student [priv]  - The sshd launches a ssh session to manage a student ssh session
3152  3145  sshd: student@pts/1   - The ssh session launched to manage the ssh session
3166  3152  -bash                 - The bash shell launched by connecting through the ssh session
3240  3166  gedit                 - The gedit command issued inside a ssh session
3166  3240  gnome-pty-helper      - Launching the gedit session across X11 
3169  3240  /bin/bash             - Launching the Terminal session inside the gedit session across X11
3269  3884  ps -ef                - Command run inside the gedit Terminal session

Hope that helps those who want to use X11 applications on the Mac OS.